The present study on the green Anolis lizard (Anolis carolinensis) represents a further test of the hypothesis that the paleostriatum of reptiles, birds, and mammals plays a basic role in species typical communicative behavior. It deals specifically with the effects of coagulative lesions of the paleostriatum on the display behavior of the green lizard. Such lesions may eliminate the challenge display, whereas similar destruction of other parts of the forebrain is without effect. BIBLIOGRAPHIC REFERENCES: Greenberg, N. B.: A neuroethological study of the display behavior in the lizard Anolis carolinensis. Amer. Zool. 17: 191-201, 1977.